1. Field of the Invention
The present invention relates to fodder additives for domestic animals, and to a process for preparing such fatty fodder additives making it possible to increase the content of omega-3-fatty acids and decrease the content of cholesterol in meats from domestic animals fed with such fodder additives.
2. Description of the Background
Methods for producing dehydrated soap powders to solve the problems of handling liquid fats used in such soap powders and methods for producing powdered fats in order to reduce their autoxidation are known as shown in U.S. Pat. Nos. 3,892,880, 3,973,046, 4,021,582 and 4,007,284 and PCT/SE 87/00419.
Among the conventional methods employed in obtaining fatty acid powders is a cold spray dray method comprising the steps of mixing the fat with an emulsifier and protein carrier, solidifying the resulting mixture in an air blast chamber at -30.degree..about.5.degree. C. and adding a powdered diluent, such as starch, in order to avoid clumping. Alternatively, an emulsion containing fat, emulsifier, water, skim milk and the like can be spray dried in air at 120.degree..about.170.degree. C.
A fatty acid powder may also be obtained by hydrolyzing a fat with strong acid or alkali, adding a metal salt thereto to precipitate the salt of fatty acid, removing the remaining acid or alkali with water and then drying it. Although the products prepared by the above mentioned methods are easy to handle, the product made from the fatty acid salt suffers an increased rate of fat oxidation as the chemical state changes from triglyceride to ester to free fatty acid, and lastly to the metal salt of the fatty acid. Consequently 80.about.90% of fatty acid within the free fatty acid salt ends up as a saturated fatty acid. Further, since most spraydried products have a high content of saturated fatty acids, they have disadvantages when used for aminal fodder to produce meat with the high content of omega-3-fatty acids and the low content of cholesterol. There is also a problem of autoxidation after prolonged storage. Furthermore, because the liberation of metal components, Ca or Na from the fatty acid by acidity of stomach proceeds slowly and due to the higher melting points of these salts, animals cannot normally absorb the fatty acids in the small intestine.